RU2476323C2 - Perfected method and device for making flat-bottom pad-like package - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to making flat-bottom pad-type packages to be arranged vertically on bottom transverse gasket that has no wedges and is intended for retail trade of snacks. Proposed method is implemented at vertical packing automatic machine including guide tube, bending device and two lateral bending elements.

EFFECT: package from extruded sleeve with open end in folding face seal to make multiple flaps, folding every flap downward below package bottom.

20 cl, 27 dwg

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a flat-bottomed bag of a pillow type, which is manufactured using a modified vertical molding-filling-capping machine, and a method for its manufacture, which provides an integral package for the retail sale of snack foods.

Description of the prior art

Many snack foods, such as chips, pretzels, etc., are packaged in very thin packaging films. These packages can be made on vertical molding-filling-capping machines, in which, as their name implies, they form a bag, fill it with product and seal the filled bag. One example of a vertical pillow forming-filling-capping machine for making bags of the pillow type is illustrated in FIG. 1 of US Pat. No. 6,718,739. In such machines, a packaging film is fed from a roll and a vertical sleeve is formed from the film around the cylinder for feeding the product. The vertical sleeve is sealed in a vertical direction along the length, as a result of which a back seal is formed. The machine, using a pair of heat-sealing pliers, forms a transverse seal on the sleeve. This transverse seal serves as an upper seal for the downstream bag and a lower seal for the upstream fill and mold bag. A packaged product, such as potato chips, falls through the cylinder to feed the product into the formed sleeve and remains in the sleeve above the lower transverse seal. After filling the bag, the film in the form of a sleeve is pushed down to extend another segment along the length of the bag. A transverse seal is formed above the product, as a result of which a bag is obtained and the product is sealed inside the bag simultaneously with the formation of a film in the form of a sleeve above the product. The bag located below the transverse seal is separated from the rest of the film in the form of a sleeve, for which an incision is made through the seal area. One example of a resulting pouch-type standard bag is shown in FIG. 3 of US Pat. No. 6,722,106.

In such a process, a packaging film of a composite polymer material obtained in a film converter is typically used. For example, in one of the prior art composite films used for packaging potato chips and similar products in standard pouch-type bags, a densified inner or product-facing layer is used, which is typically metallized oriented polypropylene (“OPP”) or metallized polyethylene terephthalate ("PAT"). A sealing layer located on the side of the metallized film facing the product ensures the formation of a tight seal using transverse heat-sealing pliers at a lower temperature than the melting temperature of the film. Standard prior art sealing layers comprise a copolymer of ethylene and propylene and a ternary copolymer of ethylene, propylene and butene-1. The metallized film layer, which is usually metallized by applying a thin layer of aluminum, provides excellent barrier properties.

The barrier properties of one or more layers are important to protect the product inside the package from light, oxygen or moisture. Such a need exists, for example, for the protection of foodstuffs, which may be at risk of loss of flavor, loss of freshness or spoilage if the barrier properties are insufficient to prevent the passage of light, oxygen or moisture into the package.

Adjacent to the metallized inner layer is a layer, usually consisting of extruded polyethylene, and an outer paint layer or a layer with graphic images. The ink layer is commonly used to represent graphic images that are visible through the transparent outer layer, which is usually OPP or PET. The total thickness of this prior art film is typically less than 225 units. Such a film is well known in the art and is described with reference to FIG. 1 in US Pat. No. 7,189,300, the contents of which are hereby incorporated by reference.

The prior art film described above is ideally applicable for use in vertical molding and packaging machines for packaging food products. In addition, through the use of OPP or PET as the outer layer and inner layer, any surface of the film can be thermally welded to any other surface during the formation of transverse seals or the reverse seal of the package.

Each seal in each package is airtight or impermeable even with changes in pressure. Without a tight seal, any barrier properties of the film that prevent the penetration of oxygen, moisture or odors from the outside into the product in the package are not effective. Sealed seals are especially important for preserving the aroma and freshness of snack foods. In areas where the package has a reverse seal, folds or wedges, additional layers of material are created at the seal, but this problem is exacerbated by thicker packaging materials, additional folds in the package design and smaller packages.

One of the disadvantages of pillow-type bags is that they have a narrow, single-edged base formed by a lower transverse seal, and for this reason such packaging known from the prior art are unstable and unable to stand on their own (for example, without relying on anything) on lower transverse seal. It would be desirable to create a package in the form of a bag such as a pillow, capable of independently standing on the lower transverse seal.

Figures 1a-1d show a vertical stable bag 100 having a front side 102 defined by an upper transverse seal 120 and a lower transverse seal 130. Also shown is a side 110 with a sealed wedge 112 adjacent to the lower transverse seal 130 and an open wedge 114 adjacent to the upper transverse seal 120. A wedge is created on the packaging side 110 when four layers of film are captured, since when creating a transverse seal, transverse heat-sealing pliers push or bend the film inward and seal its layer and. To obtain a wedge, it is not necessary that the transverse seals actually tightly connect all four layers of the packaging film, as shown by the example of open wedge 114. However, by tightly connecting all four layers, a closed wedge 112 can be obtained.

As shown in FIGS. 1c and 1d, four layers of film are also hermetically connected near the middle of the back side of the package 106 in the areas indicated by 127, 137 if a weld is used as the back seal 140. Since such an overlapping film is absent on the side of the package and is not the result of pushing or folding inward, such areas are not considered a wedge from the point of view of this application.

Used in the description, the term "wedge" means a wedge on the side 110 of the package and includes both open wedges 114 and closed wedges 112.

It is shown that the front side of the package 102 and the back side of the package 106 are connected on the sides by thermally welded folds 104 that extend from the upper transverse seal 120 to the lower transverse seal 130. The packaging shown in FIGS. 1a-1g is similar to the packaging described in US Pat. 5398486. The package shown in figa-1g, created by a method similar to the method described above with reference to the prior art. However, in order to form side wedges 110 on each side of the bag, the vertical forming-filling-capping machine should be substantially modified by adding two movable devices on opposite sides of the sealing carriage, which move in and out to come into contact with the packaging film and form the crease, which becomes the side 110 shown in figa-1d. In addition, instead of using one sealing device to make the back seal 140 for the packaging shown in FIGS. 1a-1d, an additional device is required for heat sealing each fold 104, which is created to give the package additional stability. Therefore, a total of five vertical sealing devices are used. Methods for creating such vertical folds 104 are described and proposed in US patents 5862652 and 3785112.

As indicated above, it is important that the transverse seals of each package made of this film are sealed or impermeable transverse seals. This is especially important in the case of foodstuffs suitable for long-term storage with low moisture content and / or other products exposed to oxygen and / or moisture.

On fig.1g shows a perspective rear view in terms of the packaging known from the prior art, shown in figa, and illustrates the relative position and part of the problem areas 125, 126, 127 of the transverse seal 120. On fig.1d shows an enlarged view in plan of the cross section problematic section 125 of the packaging shown in Fig. As shown in FIGS. 1d and 1e, each region 121 and 123 of the upper transverse seal 120 has four layers of film that are to be hermetically connected, and region 122 has only two layers except for the intersection with the reverse seal. Similarly, if a lap joint is used to obtain the reverse seal 140, section 127 will have three layers of packaging film, and when using a weld, section 127 will have four layers of packaging film. Due to a change in the number of layers of the packaging film in the packages, triangular shaped capillary leaks, point leaks or voids 150 (shown in FIG. 1e) can form in the manufacture of side wedges 110 in the packaging film. Similar voids are formed in each problem area indicated by 125, 126, 127. Fig. 1c shows the positions in which these problem areas 135, 136, 137 can form on the lower transverse seal 130. Problem areas can form in open wedge packages. 114, for example, in the upper part of the package illustrated in FIG. 1d, or in packages with a closed wedge 112, for example, problem areas 135, 136, 137 in the lower part of the package illustrated in FIG.

According to the prior art solution, in order to prevent point leaks, it is required in a certain way to modify the film for pillow type packages known in the art. For example, although the upper and lower transverse seals 120, 130 can potentially have problem areas 127, 137, as shown in FIGS. 1c and 1d, such problem areas can be eliminated by using the film described in patent application US 2007/0128386, assignee which is the assignee of the present invention.

Unfortunately, such a solution known from the prior art still requires modification of the film and is not able to satisfactorily eliminate the problem areas 125, 126, 135, 136, which can facilitate the penetration of oxygen and moisture into the package through the capillary voids 150 shown in fig.1d.

Another prior art solution for pinpoint leakage is to increase the amount of sealing material in the product-facing layer, such as the OPP-facing layer, by a factor of two or three. Another solution to overcome this drawback is to use an additional film layer to fill capillary voids. The additional film layer is usually a linear low density polyethylene with a thickness of 1-2.5 mils (100-250 units), which should be layered on the inner metallized layer of the OPP. Therefore, sequential layering is usually required to obtain the required multilayer film and substantially more film material should be consumed than for the manufacture of a standard package in the form of a pillow-type bag. The film thickness typically used for wedge packs generally exceeds 300 units, which means at least about 33% more film consumption than standard packs in the form of a pillow-type bag.

For example, US Pat. No. 7,122,234 teaches that the laminate used to make such packages should have sufficient flexural rigidity to be used in a continuous high-speed packaging process. According to the '234 patent, sufficient stiffness is achieved when the thickness of the laminate exceeds 110 micrometers or 433 units (1 micron or micrometer is 3.937 units; 100 units = 1 mil = 0.001 inch). European Patent Application 1283179 describes microwave heating packaging for food products sold under the trade name TETRAWEDGE. When measuring the thickness of the TETRAWEDGE package, it was found to be 12.5 or 1250 units. One of the obvious consequences of using such a thick material is that the folds of the packaging material are configured before forming the package so that the material can be bent along the inclined corners of the side walls and along the corners of the base. Similarly, US Pat. No. 5,505,075 discloses that crease lines must be impressed or otherwise pressed into the surface of the packaging material. It would be desirable to make a flat-bottomed bag of the pillow type using the same film used in the pillow-type packaging known in the art without compromising the sealing properties of the transverse seal.

According to one of the features of the invention, the package must be made in such a way that it does not have open or closed wedges, and problem areas on the upper or lower transverse seal, which are formed due to changes in the number of layers, and transition areas capable of creating capillary ones are minimized. voids 150 in transverse seals. According to one aspect of the invention, the package must have three or more distinct edges defining its bottom so that the package can stand vertically on the lower transverse seal. According to one of the features of the invention, the package must be made of the same film material and have the same film thickness as standard packaging in the form of a bag like a pillow. According to one of the features of the invention, the package is made of film material without the need to imprint or otherwise press the crease lines into the packaging film.

Summary of the invention

In one embodiment of the present invention, there is described a method of manufacturing a flat-bottomed bag of the pillow type, comprising the steps of forming a lower transverse seal, using a sliding part to form the bottom of the package with predetermined edges and valves, folding the transverse seal and folding the valves below the package. In one embodiment of the present invention, a flat-bottomed pad type wedge-free pillow package that is capable of standing on a lower transverse seal is described. An embodiment of the present invention describes an improved vertical molding-filling-capping machine having an extendable and retractable sliding part below a hose product, a bending device for folding the transverse seal, and at least two lateral bending elements for folding valves formed by the sliding part in the extended position.

Other features, embodiments, and features of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. The accompanying description of the drawings are schematic and not drawn to scale. Identical or predominantly similar elements illustrated in the various figures are denoted by the same reference numerals. For clarity, not all elements are indicated by positions on each figure. In addition, not all elements of each embodiment are shown, unless this is required to be understood by those skilled in the art. The contents of all referenced patent applications and patents are hereby incorporated by reference in their entirety. In case of conflict, preference is given to this application, including definitions.

Brief Description of the Drawings

The appended claims contain novelty elements considered to be distinguishing features of the invention. However, the invention itself, as well as the preferred embodiment, its additional objectives and advantages will be best understood from the following detailed description of explanatory embodiments in combination with the accompanying drawings, in which:

on figa shows a perspective front view of the packaging known from the prior art, which stands on the lower transverse seal,

on figb shows a side view of the prior art packaging shown in figa,

on figv shows a perspective view from below and behind the packaging known from the prior art, shown in figa,

on figg shows a perspective rear view in plan of the packaging known from the prior art, shown in figa,

on fig.1d shows a top view of the cross section of part of the packaging shown in fig.1d,

on figa shows a perspective front view of a flat-bottomed package type pillows made according to one of the embodiments of the present invention,

on figb shows a side view of the packaging shown in figa,

on figv shows a perspective view from below and behind the packaging shown in figa,

on fig.2g shows a perspective rear view in terms of packaging shown in figa,

on figa-3zh shows perspective views illustrating the sequence of operations of forming a package according to one of the embodiments of the present invention,

on figa-4g shows a perspective view illustrating the sequence of operations of forming a package according to one of the embodiments of the present invention,

5a-5g are perspective views illustrating a process for forming a packaging film according to an embodiment of the present invention.

Detailed description

FIG. 2 a shows a perspective plan view from the front of a package in the form of a flat-bottomed bag of a pillow type made according to one embodiment of the present invention. On figb shows a side view of the packaging shown in figa. On figv shows a perspective view from below and behind the packaging shown in figa. On fig.2g shows a perspective rear view in terms of packaging, shown in figa. As shown in FIGS. 2a-2d, in one embodiment of the present invention, there is provided a flat-bottomed bag or package 200 such as a pad without folds or wedges on the sides of the package. Instead, in one embodiment, the package according to the present invention has a side 210 located between the front surface 202 and the rear surface 206, which tapers up from the lower portion 212 adjacent to the lower edge 262, up to the upper transverse seal 220. Therefore, the portion 214 is close the upper transverse seal 220 according to the present invention is similar to the area near the upper transverse seal of the prior art pillow bag package shown in FIG. 3a of US Pat. No. 6,722,106, nly both packages have no gussets adjacent the top transverse seal as clearly shown in Figures 2a-2d.

As shown in FIG. 2c, the package of the present invention has a pair of inwardly folding flaps 260 that are located below the bottom 250 of the package. FIG. 2c further shows a lower transverse seal 230 oriented substantially perpendicularly to an upper transverse seal 220. In one embodiment, a portion of the lower transverse seal 230 on inwardly folding flaps 260 is thermally welded to the bottom 250. The packaging bottom 250 shown has a substantially rectangular shape. In one embodiment, the contour of the bottom of the package 250 has predominantly perpendicular front and rear edges 252, whereby the bottom 250 is predominantly perpendicular to the front surface 202 and the rear surface 206. In one embodiment, the contour of the bottom of the package 250 has a predominantly perpendicular side edge 262, whereby the bottom 250 is predominantly perpendicular to side 210. Those skilled in the art will understand that front surface 202, rear surface 206 and sides 210 are slightly angled enshim than a right angle to the bottom 250 of the narrowing sides 210 from bottom to top.

On figa-3g shows a perspective view illustrating the sequence of operations of forming a package on an improved vertical molding-filling-capping machine according to one of the embodiments of the present invention. For simplicity, the upper part of the vertical molding-filling-capping machine is not shown in figb-3zh. A flexible packaging film 301 having barrier properties is fed from a roll (not shown) and passed through a forming device 316, which forms a vertical sleeve from the film around the guide tube 318, as shown in FIG. 3a. As used herein, a flexible packaging film having barrier properties means a flexible film that transmits oxygen at a rate of less than about 150 cubic cm / m ² / day (ASTM D1434) and transmits water vapor at a rate of less than about 5 gram / m ² / day (ASTM F372-99).

5a-5g are perspective views illustrating a process for forming a packaging film according to one embodiment of the present invention. Next, with reference to FIGS. 3a-3g and 5a-5g, molding of the package shown in FIGS. 2a-2g will be described. As shown in FIGS. 3a and 5a, as the sleeve is pulled down by the drive belts 320, the vertical welding device 322 seals the vertical sleeve from the film, resulting in a back seal 240. As shown in FIG. 3a, the guide tube 318 has a sliding part 330 located below the guide tube 318. In the illustrated embodiment, the extension portion 330 has in the extended position a pair of valves. As used herein, an extended position refers to a sliding portion 330 oriented so as to externally stretch a sleeve film after forming the lower transverse seal 230. In the illustrated embodiment, the extended position is a position in which the sliding portion 330 is parallel to the guide tube portion 318 to which the sliding part 330 is attached.

As shown in FIGS. 3b and 5b, the sheet of film 301 is pulled down below the guide pipe 318. Using a pair of welding pliers 326, a lower mechanical seal 230 is created below the guide pipe 318, the sliding part 330 of which is in the retracted position to obtain an open end sleeve . As used herein, the term “retracted position” refers to the position of the extension portion 330, which allows a pair of welding tongs 326 to create a lower transverse mechanical seal below the guide tube 318. The flexible valves forming the extension portion 330 shown in FIG. 3b can be made of spring steel 0.035 inches thick or any other flexible material. Such an embodiment is advantageous in that it allows the flexible valves to be bent inwardly into the retracted position by actuating the locking mechanism 340 closing the welding tongs 326 to create a transverse seal and minimize or prevent wrinkling.

As shown in FIGS. 3c and 5c, after the formation of the lower transverse seal, the closing mechanism 340 is turned off, and the flexible valves 330 are automatically bent outward again into an extended position, thereby forming a bottom 250 of the package having a pair of outwardly extending valves 260, as best shown in figv. The transverse seal 230 rises higher as the sliding portion 330 moves to the extended position and the bottom 250 of the package is outlined.

Then, at a level above the welding tongs 326 and below the extended extension portion 330, a bending device 350 for folding the lower transverse seal 230 can be actuated. In one embodiment, under the influence of the residual heat that the welding tongs 326 transmit to the lower transverse seal, the folded lower transverse the seal adheres to the bottom of the package after activating the bending device 350. In one embodiment, the bending device 350 has heated edges. After actuating the bending device 350, the valves 260 are predominantly bent downward. Such bending of the valves 260 helps to ensure their capture by the lateral bending elements 360, as discussed below. The product may be discharged through the guide tube 318 at any time after actuating the forks 350 and forming the lower seal 230 (as shown in FIG. 5c) by folding.

On figg shows another stage of forming a package according to one of the embodiments of the present invention. The side bending elements 360 are positioned in height so that they are below the bending device 350 and above the ends of the valves 260. As shown in FIGS. 3d and 5g, a pair of side bending elements 360 bend each of the above-mentioned valves 260 inward and below the bottom 250 of the package. In one embodiment, the bending device 350 remains below the bottom 250 of the package while the bending elements 360 bend the valves 260 below both the bottom 250 of the package and the bending device 350. In one embodiment, the heat of the bending device 350 and / or the bending elements 360 softens the outer film layers of the valves 260 and the bottom 250 of the package, which helps melt and tightly connect the valves 260 with the bottom 250 of the package. In one embodiment, the bending device 350 is a forks having at least two fingers. In one embodiment, the bending device 350 is a three-finger forks that advantageously provide an open area for contact between the bottom of the package 250 and the valves 260, as shown in FIG. Since the lower transverse seal 230 is still relatively hot due to the effects of heated welding tongs 326, in one embodiment, due to the residual heat, the lower transverse seal on the valves 260 is hermetically connected to the lower transverse seal on the bottom 250 of the package in open areas between the fingers of the bending device 350. In one embodiment, a pedestal 370 (shown in FIG. 3c) is located below the guide tube 318 and inside the extension portion 330. In one embodiment, the pedestal 370 is advantageously flush with the sliding portion 330 in the extended position.

On fig.3d shows a perspective view from below of the next stage of one of the embodiments of the present invention. As shown in FIG. 3d, the lateral bending member 360 has a holder 364 for the pivotable sliding part 362. After the side bending members 360 bend the valves 260 below the bottom 250 of the package, the pivoting sliding part 362 fits on the holder 364, which is flush with each side bending element 360, moves up in the direction shown by the arrows, and comes into contact with the pedestal 370 shown in figv. Therefore, as shown in FIGS. 3d and 5g, the rotary sliding parts 362 create vertical pressure between the respective valves 260 and the bottom 250 of the package. The pedestal 370 (shown in FIG. 3c) holds the bottom of the package 250 in place so that pressure is generated between the valves 260 and the bottom 250 of the package. Since the transverse seal 230 retains the residual heat of the heated welding tongs and taking into account the pressure that the rotary sliding portion 362 exerts on the valves and the pedestal 370, in one embodiment, the transverse seal portion on the valves 260 is hermetically connected to the transverse seal portion at the bottom 250 of the package. In one embodiment, the lateral bending members 360 may be heated, and in one embodiment, the pivotable sliding portion 362 and / or pedestal 370 is heated to further contribute to the formation of a seal between the valves 260 and the bottom of the package.

FIG. 3e shows a perspective bottom view of the next stage of one embodiment of the present invention. After the valves 260 are folded down and optionally hermetically connected to the bottom 250 of the package, the bending device 350 can be removed from under the bottom 250 of the package.

Figure 3g shows a perspective view from below of one of the stages of implementation of the present invention. As shown in FIG. 3e, then the bending elements 360 can be moved outward from under the bottom 250 of the package. After that, the sheet of film can be stretched down to create the upper transverse seal.

Figures 4a-4g are perspective views illustrating a process for forming a package on an improved vertical molding-filling-capping machine according to one embodiment of the present invention. For simplicity, the upper part of the vertical molding-filling-capping machine is not shown in figb-4zh. A flexible packaging film 301 having barrier properties is fed from a roll (not shown) and passed through a forming device 316, which forms a vertical sleeve from the film around the guide pipe 318. As the sleeve is pulled down with drive belts 320, the vertical welding device 322 seals the vertical a sleeve of film, resulting in a back seal 240. As shown in FIG. 4a, the guide pipe 318 has an extension 430 below the guide pipe 318. In the illustrated embodiment, 4a-4e, the sliding portion 430 is a sliding portion that is capable of smoothly moving in the vertical direction between the retracted position and the extended position. The sliding part is able to move inside the guide tube 318 and can be attached to the control cylinder of a pneumatic or other applicable rod assembly to move the sliding part as necessary. Such sliding parts are known in the art, an example of which is US Pat. No. 5,505,040, the contents of which are hereby incorporated by reference.

As shown in FIG. 4b, the film sheet 301 is pulled down below the guide pipe 318. As shown in FIGS. 4b and 5b, a pair of welding tongs 326 create a lower mechanical seal 230 below the guide pipe 318 with the extension 430 in the retracted position.

As shown in FIGS. 4c and 5c, after the formation of the lower transverse seal 230, the sliding part 430 moves to the extended position, thereby forming a bottom 250 of the package having a pair of outwardly extending valves 260, as best seen in FIG. The transverse seal 230 moves higher as the sliding portion moves into the extended position and the bottom 250 of the package is outlined.

Then, at a level above the welding tongs 326 and below the extended extension portion 430, a bending device 350 for folding the lower transverse seal 230 can be actuated. In one embodiment, under the influence of the residual heat that the welding tongs 326 transmit to the lower transverse seal, the folded lower transverse the seal adheres to the bottom of the package after activating the bending device 350. In one embodiment, the bending device 350 has heated edges. After actuating the bending device 350, the valves 260 are predominantly bent downward. Such bending of the valves 260 helps to ensure that the valves 260 are gripped by the lateral bending members 360, as discussed below. The product may be discharged through the guide tube 318 at any time after actuating the forks 350 and forming a lower seal (as shown in FIG. 5c) by folding.

On Figg shows another stage of forming a package according to one of the embodiments of the present invention. The lateral bending elements 360 are positioned in height so that they are below the bending device 350 and above the ends of the valves 260. As shown in FIGS. 4g and 5g, a pair of side bending elements 360 bend each of these valves 260 inward and below the bottom 250 of the package. In one embodiment, the bending device 350 remains below the bottom 250 of the package while the bending elements 360 bend the valves 260 below both the bottom 250 of the package and the bending device 350. In one embodiment, the heat of the bending device 350 and / or the bending elements 360 softens the outer layers of the film of the valves 260 and the bottom 250 of the package, which helps melt and seal the valves 260 with the bottom 250 of the package. In one embodiment, the bending device 350 is a forks having at least two fingers. In one embodiment, the bending device 350 is a three-finger forks that advantageously provide an open area for contact between the bottom 250 of the package and the valves 260, as shown in FIG. Since the lower transverse seal 230 is still relatively hot due to the effects of heated welding tongs 326, in one embodiment, due to the residual heat, the lower transverse seal on the valves 260 is hermetically connected to the lower transverse seal on the bottom 250 of the package in open areas between the fingers of the bending device 350. In one embodiment, a pedestal 470 is located below the guide tube 318 and inside the extension portion 430 (shown in FIG. 4c). In one embodiment, the pedestal 370 is advantageously flush with the sliding part 430 in the extended position. The pedestal 470 can be attached to the sliding part 430 and move with it.

Fig. 4e shows a perspective view from below of the next stage of one of the embodiments of the present invention. As shown in FIG. 4e, the lateral bending member 360 has a holder 364 of the rotatable sliding portion 362. After the lateral bending members 360 bend the valves 260 below the bottom 250 of the package, the rotary sliding portion 362 fits on the holder 364, which is flush with each lateral bending element 360, moves up in the direction shown by the arrows, and comes into contact with the pedestal 470 shown in figv. Because of this, as shown in FIGS. 4e and 5d, the rotary sliding parts 362 create vertical pressure between the respective valves 260 and the bottom 250 of the package. A pedestal 470 (shown in FIG. 4c) holds the bottom of the package 250 in place so that pressure is generated between the valves 260 and the bottom 250 of the package. Since the transverse seal 230 retains the residual heat of the heated welding tongs and taking into account the pressure that the rotary sliding part 362 exerts on the valves and the pedestal 470, in one embodiment, the transverse seal part on the valves 260 is hermetically connected to the transverse seal part on the bottom 250 of the package. In one embodiment, the lateral bending members 360 may be heated, and in one embodiment, the pivotable sliding portion 362 and / or pedestal 470 is heated to further contribute to the formation of a seal between the valves 260 and the bottom of the package.

FIG. 4e shows a perspective bottom view of the next stage of one embodiment of the present invention. After the valves 260 are folded down and optionally hermetically connected to the bottom 250 of the package, the bending device 350 can be removed from under the bottom 250 of the package.

Figure 4g shows a perspective view from below of one of the stages of the implementation of the present invention. As shown in FIG. 4e, then the bending elements 360 can be moved outward from under the bottom 250 of the package. After that, the film sheet can be stretched down, where an upper transverse seal is created.

Figures 5a-5g are partial simplified perspective views of the back and bottom, illustrating the sequence of manufacturing the bottom shown in figv packaging from a packaging film. Vertical molding, filling and capping equipment is not shown. On figa illustrated a film in the form of a sleeve with a reverse seal 240, which corresponds to a film in the form of a sleeve, illustrated in figa and 4A. On figb shows a film in the form of a sleeve with an open end after creating a lower transverse seal, which corresponds to a film in the form of a sleeve, shown figb and 4b. Fig. 5c shows the bottom of the package 250 with the curved lower transverse seal 230 and the lip 252 predominantly perpendicular to the rear surface 204 of the package. Shown in figv film corresponds to a film in the form of a sleeve shown in figv and 4B. Fig. 5g shows a package 250, in which a bottom is formed with a pair of fold-in valves 260 located below the bottom of the package, and which corresponds to the package shown in Figs. 3d and 4d. For the manufacture of the package according to the present invention, a transverse seal is created on the film in the form of a sleeve with an open end, as shown in Fig. 5b. Edges 252 are then formed to outline a flat bottom 250 of the package. As a result of the formation of the edges 252, a pair of valves 260 are created, as shown in FIG. The valves 260 are then folded inward and below the bottom 250 of the package to create side edges 262.

The present invention has several advantages. Firstly, since the package does not have wedges, a flexible film of a smaller thickness can be used by reducing the number of problem areas in which point leaks can form. The flat bottom package of the present invention can be made of a film with a thickness of less than 180 units. Therefore, at least 33% less film is consumed in the manufacture of a flat-bottomed pillow-type bag than in the manufacture of the bag of the prior art according to the embodiment illustrated in FIGS. 1a-1d. In one embodiment, the film used in the present invention consists of a metallized OPP layer onto which a sealing layer and a polymer layer with an imprint applied on the back are laminated with polyethylene or another suitable adhesive layer. So, in one embodiment, the package of the present invention is made of the same film as the pillow type package. The invention provides packaging and a method for manufacturing it from a flexible material without having to imprint or otherwise press into the packaging film of the crease line prior to its manufacture.

One of the advantages of the present invention is that the upper and lower transverse seals are made without side wedges. In addition, since the number of points of formation of pinholes is reduced, the packaging according to the present invention provides a more constant shelf life of the contents. The present invention provides a method of manufacturing flat-bottomed bags of the pillow type by modifying a standard vertical molding-filling-capping machine.

Although the invention has been specifically considered and described in relation to a preferred embodiment, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (20)

1. A method of manufacturing a bag-type bag with a flat bottom, comprising the steps of:
a) form the sleeve of the packaging film on a vertical molding-filling-capping machine,
b) create a mechanical seal on said sleeve, while said mechanical seal is made without folds,
c) bending said mechanical seal with a bending device to create a plurality of valves, and
d) each of said valves is folded down and below said bottom of the package. 2. The method according to claim 1, wherein a first mechanical seal is created using a pair of welding pliers to obtain an open end sleeve, said first mechanical seal being created below the guide tube with the extension part in the retracted position, and the said extension part is moved to extended position to form the bottom of the package with a pair of outward protruding valves. 3. The method according to claim 2, in which when moving said sliding part, the sliding part is further extended downward from the inside of said guide tube. 4. The method according to claim 2, in which the said sliding part is moved to the extended position by actuating the locking mechanism. 5. The method according to claim 2, in which the aforementioned first mechanical seal is bent using a fork, having at least two fingers and an open area between them. 6. The method according to any one of the preceding paragraphs, in which said sleeve consists of a film with a thickness of less than 180 units. 7. The method according to claim 2, in which the aforementioned first mechanical seal is bent so that a bent mechanical seal is formed, which is mainly located at an angle of 90 ° to the upper mechanical seal. 8. The method according to claim 2, in which said valves are hermetically connected to said bottom of the package. 9. The method according to claim 1 or 2, wherein in step d), a vertical pressure is additionally created between each of said valves and said bottom of the package. 10. A flat-bottomed package in the form of a pad-type bag without wedges, wherein said flat bottom has a pair of inwardly folded flaps below said package bottom, said package containing a film of a thickness of less than about 180 units. 11. The package of claim 10, which has one vertical seal. 12. The package of claim 10, which has the ability to stand on its own on the lower transverse seal. 13. The package of claim 10, additionally having at least two lower edges, which are mainly perpendicular. 14. The package of claim 10, wherein said inwardly folded valves are thermally welded to said bottom of the package. 15. The package of claim 10, which is made from (a) a flexible film that transmits oxygen at a rate of less than about 150 cubic cm / m ² / day or transmits water vapor at a speed of less than about 5 gram / m ² / day, or (b) a film consisting of a layer of metallized oriented polypropylene, onto which, using polyethylene or another suitable adhesive layer, a sealing layer and a polymer layer with an imprint applied on the back are laminated. 16. A vertical molding-filling-capping machine having:
a guide tube with a sliding part that is capable of moving between the extended position and the retracted position;
a bending device for folding the lower transverse seal near the bottom of the package to create a pair of valves; and
a pair of side bending elements, each of which fixes each valve below the bottom of the package. 17. The machine of claim 16, wherein said sliding part comprises a telescopic part that can slide into said guide tube, or said sliding part comprises a pair of flexible valves. 18. The machine according to clause 16, in which each of the aforementioned side bending elements further has a rotary sliding part, 19. The machine of claim 16, further comprising at least one pedestal below said guide tube. 20. The machine according to clause 16, which consists of one vertical capping device.

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